1. Field of the Invention
The invention relates generally to valving apparatus and particularly to valving apparatus for manually controlling flow of gas under pressure.
2. Description of the Prior Art
Controllable valves are well known in the art, such valves being capable of actuation through a variety of mechanisms including mechanisms which are manually manipulatable. As an example of prior art valves operable in a manual fashion, U.S. Pat. No. 2,408,006 to Smith describes a hydraulic valve having a spring-loaded pin element which can be displaced between flow and non-flow positions by means of a rotary cam controlled by a handle which can be manually grasped for rotation of the cam. A similar cam-controlled valve is described by Edick in U.S. Pat. No. 1,509,862, a thumb-turn element rotating a cam member which biases a spring-biased plunger element between positions which allow flow of fluid through a valve aperture. Strout, in U.S. Pat. No. 2,225,759, describes a spray gun nozzle having a valving element actuable on inward movement of a pin, a cam element which is rotated through connection to a handle being turned to displace the pin. The handle of Strout can be manually grasped to move the cam element between open and closed positions. Pickup, in U.S. Pat. No. 2,129,100, describes a dual cam mechanism which alternately displaces spring-loaded pin elements between positions which control flow of a fluid. In U.S. Pat. No. 1,774,918, Hall et al describe a manually operable handle which biases a cylindrical element against a pin to open a valving element in a valve apparatus. Whittemore, in U.S. Pat. No. 3,515,442, describes a hydraulic brake lock comprising a valving element actuable on displacement of a pin to allow fluid flow. While the prior art has provided valving apparatus of many types and capable of a variety of different functions, the prior art has not provided the particular valving apparatus of the present invention wherein temporary attachment can be made between a refrigeration apparatus which is to be charged with a pressurized refrigerant and a source of refrigerant, which source can be a portable source, with the flow of refrigerant being controllable by finger manipulation of a cam element in the present valve apparatus, the present valve apparatus being portable and being rapidly attached and detached from the refrigeration apparatus as well as from the source of refrigerant without the use of tools of any description. The invention thus provides cost and operational advantages.